Strong genetic component to childhood obesity

Childhood body weight is strongly influenced by genes according to new research published today in the International Journal of Obesity . Previous research has shown that obesity runs in families, and twin studies suggest that this is largely due to genetic factors, with heritability estimates over 50%. 32 genes have been identified as risk factors for obesity but previous analyses suggest that these genes alone cannot fully explain the high level of heritability in childhood obesity, as together they explain only 2% of individual differences in childhood body weight. This has led to a problem of 'missing heritability'. In this study, researchers used a new method called Genome-wide Complex Trait Analysis (GCTA), to investigate the molecular genetic heritability of body weight in children. GCTA takes advantage of the fact that some people are more genetically similar to one another than others, by chance; and looks to see whether individuals who just happen to be more genetically similar might also be more similar in weight. Using this approach, GCTA estimates the combined effects of all known common genes across the whole genome, associated with childhood body weight.